A frame rate of video is a magnitude for measuring the number of display frames, with the measuring unit being frames per second (FPS) or hertz (Hz). Known frame rates of video signals are as shown in Table 1 below:
TABLE 1TelevisionMoviePALNTSC23.976 fps25 fps29.97 fps
In Table 1, the frame rate of movie video signals is 23.976 fps, and television video signals may include, for example, phase alternating line (PAL) standard video signals and national television standards committee (NTSC) standard video signals, wherein the frame rate of the PAL standard video signals is 25 fps, and the frame rate of the NTSC standard video signals is 29.97 fps.
At the same time, different types of displays have different refresh frequencies, and a refresh frequency refers to the refresh rate of a screen. The lower the refresh frequency is, the more serious the image flicks, pauses and dithers, and the more easily eyes fatigue. Currently, refresh frequencies of different types of displays are as shown in Table 2 below:
TABLE 2Liquid crystalCRT displaydisplay3D display60 Hz-85 Hz60 Hz-75 Hz120 Hz
In Table 2, the displays may include: a cathode ray tube (CRT) display, a liquid crystal display and a 3D display, wherein the refresh frequency of the CRT display is 60 Hz-85 Hz, the refresh frequency of the liquid crystal display is 60 Hz-75 Hz, and the refresh frequency of the 3D display is 120 Hz.
The display receives video signals transmitted by an image processing unit and displays the received video signals. Table 1 shows the frame rate of the video signals received by the image processing unit, and Table 2 shows the refresh frequency of the display screen. It can be seen from Table 1 and Table 2 that, the frame rate of the video signals received by the image processing unit is significantly lower than the refresh frequency of the display screen, and therefore, in the prior art, before sending the video signals to the display, the image processing unit is required to convert the video signals into video signals of which the frame rate is consistent with the refresh frequency of the display screen. Taking video signals with a frame rate of 30 Hz, and a display with a refresh frequency of 60 Hz and a resolution of 1366*768 as an example, after receiving the video signals of 30 Hz, the image processing unit converts the video signals of 30 Hz into video signals of 60 Hz, which can be displayed by the display, and outputs video signals of 60 Hz to the display and therefore, the pixel data volume transmitted to the display by the image processing unit is 1366*768*60=62,945,280 per second.
In summary, in the prior art, due to a larger amount of data transmission and a larger amount of data processing of the image processing unit, the load of the image processing unit is greatly increased, so that the image processing unit is likely to become a performance bottleneck of a display system.